jernsyklus

Jernsyklus refers to the biogeochemical cycle of iron. Iron is an essential element for most living organisms, playing a crucial role in processes like oxygen transport (hemoglobin) and electron transfer (cytochromes). The jernsyklus describes how iron moves through the Earth's lithosphere, hydrosphere, atmosphere, and biosphere.

In terrestrial environments, iron is primarily found in rocks and soils in oxidized forms, such as ferric iron (Fe3+). Weathering of rocks releases iron into the environment. Plants absorb iron from the soil, often in its reduced ferrous form (Fe2+), which is more soluble. Microbial activity plays a significant role in mediating the redox transformations of iron between Fe2+ and Fe3+, influencing its availability to plants and its mobility in ecosystems.

In aquatic environments, iron's solubility is highly dependent on pH and oxygen levels. In oxygen-rich waters, iron tends to precipitate as insoluble ferric hydroxides. In anoxic or low-oxygen conditions, iron can be reduced to Fe2+, increasing its solubility and allowing it to be transported. This process is particularly important in lakes, oceans, and groundwater.

Atmospheric iron, primarily in the form of dust particles, can be transported over long distances and deposited onto land and sea surfaces, serving as a source of iron for remote ecosystems. Biological uptake and transformations are central to the jernsyklus, with microorganisms both consuming and releasing iron, influencing its chemical state and distribution within various Earth compartments. The cycling of iron is interconnected with other nutrient cycles, such as carbon and nitrogen, and is influenced by factors like rainfall, temperature, and geological processes.